# Copied from Scalar::Util
sub looks_like_number {
  local $_ = shift;

  # checks from perlfaq4
  return $] < 5.009002 unless defined;
  return 1 if (/^[+-]?\d+$/); # is a +/- integer
  return 1 if (/^([+-]?)(?=\d|\.\d)\d*(\.\d*)?([Ee]([+-]?\d+))?$/); # a C float
  return 1 if ($] >= 5.008 and /^(Inf(inity)?|NaN)$/i) or ($] >= 5.006001 and /^Inf$/i);

  0;
}